It would have been churlish not to sample some of the local bumps whilst up there and I enjoyed a fantastic walk up to High Street (named after the Roman Road that went over the peak). The conditions changed almost instantly, as they are wont to do at this time of year, from mild and sunny to bitter cold, freezing fog and ferocious winds near the summit. The map came out to check the safe descents as visibility plummeted to about 25 metres at times but the compass stayed in the rucksack: the wind was blowing hard and very constantly from the southwest so I only needed to make sure that my right cheek stayed frozen to hold my southeasterly course down. There were also some helpful pockets of lee snow tucked into the hillsides.

In the photo above you can see how the ice has not formed symmetrically around this triangulation pillar: as we look just east of south there is no ice on the neareast northern side. This may seem counerintuitive as you might expect to find more ice on the shaded northern side, but the reason for the lack of snow on the northern side here is that this ice has been caused by moisture in the air that is near or just below freezing hitting the triangulation pillar which is below zero degrees and then freezing on impact. This is the same ‘rime ice’ effect that aircraft experience on their wings in these conditions. The sides facing into the wind will ice up and the lee sides, the northern and eastern sides in this case, will remain free of ice.

A roe deer jumped across the path in front of me as I climbed the hill and there was the red breast of a robin waiting on the branch of an ash, modelling part time for a Christmas card perhaps. The first thing that struck me on reaching the windmill was the large patch of green grass shaped like a cone to the south-southwest. A distinct snow shadow tucked away from the heavy snows of the night before. It was a clue both to the wind direction of the night before, but also the strength of the wind. The snow must have fallen in something close to a storm as the shadow stretched quite far from the base of the windmill, suggesting strong winds. This had led to some unusual effects elsewhere as well. In light winds the snow tends to accumulate on the lee of obstacles like trees, but when the wind is strong it is plastered onto the windward side where it sticks. From a navigational perspective it does not matter hugely whether the snow has stuck to the leeward or windward side predominantly, because once the orientation has been identified it will be consistent over wide areas. In fact the north-northeast of the trees all the way down the A roads from London to Chichester had shown this trademark strip of white.

The wind direction had not changed noticeably since the snow fell and I sheltered in the relative warmth of the lee of the windmill with a flask of hot chocolate, venturing out every few minutes to take photos. The two day old moon was the first object to appear after the sun, followed quickly by Jupiter in the south.

This morning I was sent this photo, by Fred Smith, a retired airline pilot who came on one of my RGS courses a few months ago and who now lives in the Caribbean. It shows the same two-day-old moon of yesterday, which is the same phase when viewed from all over the world, but the orientation changes with latitude. The faint star just visible below the moon is Mercury, which had not been visible in the cloud near the horizon in Chichester. More often than not an ‘evening star’ will be Venus, but on this occasion Mercury is far enough from the sun and Venus is hidden in the bright glare of the sun itself and impossible to see.

There are a lot of great wayfinding methods that revolve around deducing prevailing wind direction. It is always worth looking for lee build-up. It works in most parts of the world, and doesn’t matter whether we are looking for snow, sand or leaves. In this case last year’s dead and discarded corn leaves and husks lie in the lee of the westerly winds that had been dominating for the past couple of days. (Those who have been on a course will probably also have spotted the clue in the puddle and mud in the corner.)